A dual vulnerability hypothesis for seasonal depression is supported by the seasonal pattern assessment questionnaire in relation to the temperament and character inventory of personality in a general population

BACKGROUND: Personality structure obtained from the psychobiological Temperament and Character Inventory (TCI) was studied in relation to self-reported seasonal variations in mood and behavior measured by the Seasonal Pattern Assessment Questionnaire (SPAQ). METHODS: The subjects comprised 1761 adults (57.6% women) in the age range 35-85 years, enrolled in the Betula prospective random cohort study of Umea, Sweden. RESULTS: Personality profiles of subjects who reported the occurrence of a high degree of seasonal variation as such were associated with a combination of high self-transcendence (ST) and high persistence (PS), irrespective of the level of harm avoidance (HA). Subjects who reported feeling worst in winter were associated with high HA, irrespective of the levels of ST and PS. Also, subjects feeling worst in summer or experiencing overall problems with seasonal variation were associated with high HA in their personality profiles. Using the SPAQ criteria to define seasonal affective disorder (SAD) or subsyndromal SAD (S-SAD), subjects with these disorders often had combinations of high self-transcendence (ST) and high persistence (PS), but with different associations with HA. LIMITATIONS: No evaluations were made for SAD or subsyndromal SAD according to the DSM-IV or ICD 10 criteria. CONCLUSIONS: Our results relating SPAQ with TCI give support for a dual vulnerability hypothesis for seasonal depression proposed in the literature, where it is attributed to a combination of a seasonal factor and a depression factor. Examining the literature regarding the relationships between the different TCI scales and monoamine neurotransmitter functions, those relationships suggest that these two vulnerability factors for seasonal depression may be modulated by different neurotransmitter systems.     

Preventive maintenance. 'Problem recognition style' can be used to segment the market and promote healthier lifestyles

Problem recognition styles--desired state types (DSTs) and actual state types (ASTs)--have an effect on preventive health care decision making. Segmenting the market along these lines can help marketers position products and services to educate and attract people who will not see a doctor unless there is something wrong with them. Both groups expect the same benefits from preventive health care actions, but ASTs fail to act on those expectations. Therefore, marketing strategy touting the benefits of preventive health care might be futile. Educational promotional campaigns aimed at both DSTs and ASTs also are wasteful because DSTs already possess much health knowledge, lead wellness-oriented lifestyles, and practice preventive health behaviors.     

Potent inhibition of the cytochrome P-450 3A-mediated human liver microsomal metabolism of a novel HIV protease inhibitor by ritonavir: A positive drug-drug interaction.

ABT-378 is a potent in vitro inhibitor of the HIV protease and is currently being developed for coadministration with another HIV protease inhibitor, ritonavir, as an oral therapeutic treatment for HIV infection. In the present study, the effect of ritonavir, a potent inhibitor of cytochrome P-450 (CYP) 3A, on the in vitro metabolism of ABT-378 was examined. Furthermore, the effect of ABT-378-ritonavir combinations on several CYP-dependent monooxygenase activities in human liver microsomes was also examined. ABT-378 was found to undergo NADPH- and CYP3A4/5-dependent metabolism to three major metabolites, M-1 (4-oxo) and M-3/M-4 (4-hydroxy epimers), as well as several minor oxidative metabolites in human liver microsomes. The mean apparent K(m) and V(max) values for the metabolism of ABT-378 by human liver microsomes were 6.8 +/- 3.6 microM and 9.4 +/- 5.5 nmol of ABT-378 metabolized/mg protein/min, respectively. Ritonavir inhibited human liver microsomal metabolism of ABT-378 potently (K(i) = 0.013 microM). The combination of ABT-378 and ritonavir was much weaker in inhibiting CYP-mediated biotransformations than ritonavir alone, and the inhibitory effect appears to be primarily due to the ritonavir component of the combination. The ABT-378-ritonavir combinations (at 3:1 and 29:1 ratios) inhibited CYP3A (IC(50) = 1.1 and 4.6 microM), albeit less potently than ritonavir (IC(50) = 0.14 microM). Metabolic reactions mediated by CYP1A2, CYP2A6, and CYP2E1 were not affected by the ABT-378-ritonavir combinations. The inhibitory effects of ABT-378-ritonavir combinations on CYP2B6 (IC(50) = >30 microM), CYP2C9 (IC(50) = 13.7 and 23.0 microM), CYP2C19 (IC(50) = 28.7 and 38.0 microM), and CYP2D6 (IC(50) = 13.5 and 29.0 microM) were marginal and are not likely to produce clinically significant drug-drug interactions.     

Affective responses towards service providers: implications for service encounter satisfaction

This study investigates the influence of affective responses towards service providers on service encounter satisfaction within the context of health care services. A model of Service Encounter Satisfaction that incorporates affective responses is proposed and tested. The results suggest that affective responses may exert significant influence on perceived performance of the service provider. Managerial implications and future research directions are discussed.     

Evaluation of the relationship between weight change and glycemic control after initiation of antidiabetic therapy in patients with type 2 diabetes using electronic medical record data

Aims

This study evaluates the relationship between HbA1c and weight change outcomes by anti-diabetic weight-effect properties in patients newly treated for type 2 diabetes; a relationship not previously characterized.

Methods

Electronic medical records of patients with type 2 diabetes newly prescribed anti-diabetic monotherapy were assessed to identify HbA1c goal attainment [(<53 mmol/mol)] and weight change at 1-year. Anti-diabetics were categorized by weight-effect properties: weight-gain (sulfonylureas, thiazolidinediones) and weight-loss/neutral (metformin, DPP-4 inhibitors, GLP-1 agonists). Logistic regression analyses identified likelihood of attaining HbA1c goal or ≥3% weight loss by anti-diabetic category controlling for baseline characteristics. MANOVA was used to identify correlation between changes in weight and HbA1c.

Results

The study included 28,290 patients. Mean age ± sd was 61 years ± 11.8. Baseline HbA1c was 7.4% ± 1.6 (57 mmol/mol ± 17); 67.3% were prescribed a weight-loss/neutral anti-diabetic. At 1-year, more patients in the weight-loss/neutral anti-diabetic category lost weight (≥3%) than in the weight-gain anti-diabetic category (40.4% vs. 24.2%, p < 0.001) or had an HbA1c < 7.0% (<53 mmol/mol) (71.1% vs. 63.8%, p < 0.001). Those prescribed a weight-gain anti-diabetic were 53% less likely to lose weight and 29% less likely to be at HbA1c goal than those prescribed a weight-loss/neutral anti-diabetic (p < 0.001). Weight loss and HbA1c outcomes were significantly correlated (p < 0.001).

Conclusions

Weight loss of ≥3% was associated with better glycemic control in patients newly treated for type 2 diabetes. Anti-diabetics associated with weight-loss/neutrality were associated with greater weight loss and HbA1c goal attainment and may facilitate efforts to co-manage weight and glycemia in the ambulatory-care setting.     

Functional traits explain variation in plant life history strategies

Ecologists seek general explanations for the dramatic variation in species abundances in space and time. An increasingly popular solution is to predict species distributions, dynamics, and responses to environmental change based on easily measured anatomical and morphological traits. Trait-based approaches assume that simple functional traits influence fitness and life history evolution, but rigorous tests of this assumption are lacking, because they require quantitative information about the full lifecycles of many species representing different life histories. Here, we link a global traits database with empirical matrix population models for 222 species and report strong relationships between functional traits and plant life histories. Species with large seeds, long-lived leaves, or dense wood have slow life histories, with mean fitness (i.e., population growth rates) more strongly influenced by survival than by growth or fecundity, compared with fast life history species with small seeds, short-lived leaves, or soft wood. In contrast to measures of demographic contributions to fitness based on whole lifecycles, analyses focused on raw demographic rates may underestimate the strength of association between traits and mean fitness. Our results help establish the physiological basis for plant life history evolution and show the potential for trait-based approaches in population dynamics.Recent evidence for global patterns of functional variation in plants, such as the leaf economics spectrum (1, 2), the wood economics spectrum (3), and the seed size–seed number tradeoff (4, 5), has convinced many ecologists that functional traits offer the best available approach for achieving a general predictive understanding of communities and ecosystems (6, 7). Trait-based approaches are now being used to predict the outcome of community assembly (8–10), global vegetation dynamics (11), and the rate of ecosystem processes (6, 12–14). A central assumption of trait-based ecology is that morphological traits determine physiological performance, which influences vital rates and determines individual fitness and life history evolution (15, 16). However, because of the challenge of quantifying the contribution of traits to fitness, the assumed links between functional traits and life history have not been fully tested.Research in tropical and Mediterranean forests has revealed cross-species relationships between functional traits and the survival and growth rates of individuals (3, 17–24). Although these relationships provide evidence that functional traits influence vital rates, they offer only limited insight into associations between those traits and individual fitness and life history. Vital rates (e.g., survival and fecundity) represent fitness components, but their influence on mean fitness, defined as the population growth rate (λ), is best understood in the context of the full lifecycle of a species (25, 26). A significant negative correlation between wood density and individual growth (18) might not translate into a significant effect on mean fitness if individual growth has little influence on λ. Conversely, a weak relationship between a functional trait and another vital rate could have a significant effect on mean fitness if that vital rate has a strong influence on λ. Perturbation analyses, such as the sensitivities and elasticities frequently applied to matrix projection models (27), address this problem by quantifying the contribution of vital rates to λ (28), making it possible to characterize a species'' overall life history in terms of the relative importance of survival, individual growth, and fecundity to mean fitness. Species with slow life histories have population growth rates with high elasticities to survival, whereas species with fast life histories have relatively higher elasticities to individual growth or fecundity (29, 30).Armed with vital rate elasticities, we can test quantitative hypotheses about whether functional tradeoffs scale up to generate life history tradeoffs. For example, plants can allocate their reproductive effort to provision a few large seeds, which tolerate low light and resource availability and have a high survival probability, or they can spread their reproductive effort among many small seeds, maximizing fitness under high resource availability (31, 32). If this functional tradeoff at the seedling stage translates into a life history tradeoff, seed mass should be positively related to the elasticity of the population growth rate to survival and negatively related to elasticities to individual growth and fecundity. The leaf economics spectrum represents another allocation tradeoff. Species can construct long-lived, well-defended leaves that are often favored in low resource environments or build leaves that assimilate carbon quickly under conditions of high resource availability but are prone to rapid tissue loss (1, 33). Species with slow leaf economics traits, such as long leaf lifespans, low specific leaf area (SLA), and low leaf N, might also lead slow lives, characterized by high elasticities to survival and low elasticities to individual growth and recruitment. A wood economics spectrum also exists: species with dense wood tend to have higher survival but lower relative growth rates than species with soft wood (3, 34). Elasticities to survival should increase with wood density, whereas elasticities to individual growth and fecundity should decrease.The main obstacle in testing these hypotheses is availability of the detailed demographic data necessary to describe a species’ full lifecycle and estimate vital rate elasticities. We overcame this limitation by crossing the TRY Global Plant Traits Database (35) with the COMPADRE Plant Matrix Database (www.compadre-db.org/), a collection of published matrix population models. This approach produced a dataset of 222 plant species spanning a global range of biomes and perennial growth forms (Table S1), for which we have at least one functional trait measurement as well as a matrix population model that we used to calculate the elasticity of the population growth rate to each of the three vital rates: survival, growth, and fecundity (30).Our primary objective was to evaluate the ability of functional traits to explain variation across species in life history, which we quantified with vital rate elasticities. Our secondary objective was to evaluate whether inferences about life history can be drawn directly from the raw vital rates, which would save researchers the considerable time and effort required to parameterize population models and calculate elasticities. We used two statistical approaches to quantify relationships between vital rate elasticities and seed mass, wood density, and leaf economics traits (leaf lifespan, SLA, and leaf N). Dirichlet regression is a multivariate approach that accounts for the fact that the survival, growth, and fecundity elasticities for each species sum to one but does not account for phylogenetic relationships. Phylogenetic generalized least squares (PGLS) regression ignores the nonindependence of the elasticities but accounts for phylogenetic relationships. We repeated both types of regressions with plant growth form and then biome included as covariates to confirm that trait effects did not simply represent differences between trees and herbaceous species or plants adapted to different environments.     

Elastase: a predictive marker of inflammation and/or infection

The present study was undertaken to estimate elastase in biological fluids and assess its usefulness as an indicator of inflammation/infection. Elastase was measured in seminal plasma, serum, urine, and cervical specimens using a specific substrate and was expressed in arbitrary units (AU). It was found to be stable over a period of 3 weeks. The intra- and interassay variation of elastase assay was between 2.3 to 6.8% and 7.3 to 9.9%, respectively. The assay was validated by comparing it with other methods that are available for the detection of infections. Sensitivity of the assay indicating inflammation/infection in these samples varied between 70.9 to 87.3%. The results obtained suggest that the presence of elastase in specimens may be used as a nonspecific indicator and could be used to screen inflammation/infection in a limited resource setting.     

Season of birth variations in suicide methods in relation to any history of psychiatric contacts support an independent suicidality trait

BACKGROUND: Due to reports on season of birth variations in suicidal behaviour as well as in cerebrospinal fluid levels of monoamine metabolites, we investigated season of birth variations in suicide methods for completed suicides in relation to any history of psychiatric contacts. Relationships with the psychiatric diagnoses for those with psychiatric contacts were also studied. METHODS: Sociodemographic variables and suicide methods were examined for all the 693 suicide victims during 1961-1980 in V?sterbotten, Sweden. Information on any history of psychiatric contacts was obtained from psychiatric in-patient and out-patient records. RESULTS: Gender differences in the choice of suicide method were found in the group without any history of psychiatric contacts, but not in those with such a history. Only those without a history of psychiatric contacts showed season of birth variations for suicide methods -- those born during February to April were significantly more likely, and those born during October to January significantly less likely, to have preferred hanging rather than poisoning or petrol gases. These associations were stronger for the determined suicides, for males, and for urban residence. Suicide victims with a history of psychiatric contacts were significantly younger than those without. LIMITATIONS: No psychological autopsies for those without psychiatric contacts. No information on eventual contacts with general practitioners. No measures of monoamine neurotransmitters were available. CONCLUSIONS: Season of birth association for suicide methods is likely to be mediated by a suicidality trait independently of specific major psychiatric disorders. Monoamine neurotransmitters, particularly serotonin, are likely to underlie such a trait.